How do I determine my Linux box's performance bottleneck?

Question

I recently installed Ubuntu 9.04 (First time Linux desktop user) on my new netbook.

There is only a little additional software (Skype, Dropbox, AVI/MP3 Codecs), and the OS updates - and already the system hangs and gets real slow every now and again.

Maybe it just feels slow because I've moved from Google Chrome on a desktop to Firefox on a notebook; but there's definately a bottleneck - and according to the System Monitor it's not the CPU.

Before investing in a SSD, I'd like to know: what software would you recommend I use to determine this bottleneck?

Here's the specs: RAM: 2GB DDR2 800MHz. CPU: Intel Atom N270 @ 1.60GHz. GPU: Integrated. HDD: 150GB SATA Hitachi HTS54501.

I've already checked the threads Tools to find bottlenecks in hardware configuration & Will I see performance benefits from an SSD in my laptop? and they didn't quite answer my question.

Thanks.

Answer 1

Check the utilization of the following things besides the processor,

1. The 2GB RAM (if you are beyond 80%-90%, you need more of it)
   • Swap space (If you find more than 30%-40% utilization, Disk I/O may slowing you down)
   • Disk I/O (journaling and disk access speed may be holding you)

---

Checking Disk I/O is a good idea,
I'd also suggest checking the notes in EvilChookie's answer (+1 there),
particularly because you have an Atom based system.
An idle processor could also be a processor waiting for data/instructions.

Answer 2

The SYSSTAT utilities consist of a great collection of performance monitoring tools for CPU, memory, Disk I/O, and your network.

The official tutorial can be found here.

Answer 3

Just because your CPU doesn't seem overloaded by a process monitor, doesn't mean it's not the bottleneck.

Keep in mind that the processor as a whole (not just it's clock speed) will determine the overall performance of your net book:

CPU Clock: 1.6ghz
FSB: 533mhz
L2 Cache: 512kB
Single Core Processor

Remember the following:

• All I/O is CPU controlled. RAM and Hard drive requests are going to tax the CPU at some point
• All USB devices are directly dependent on the CPU. Many components are actually USB devices, especially in notebooks. Keyboard, trackpad, wireless, etc.
• Lower FSB means a slower response time.
• Single core is just not as good as a multi core processor, especially when considering the lower clock speed, and lower FSB.

All these factors contribute to slower multi tasking. Just because your activity monitor doesn't show high CPU load, doesn't mean that the CPU can't get taxed by lots of little requests (and keep in mind that a CPU can only perform one request at a time).

Answer 4

My favourite is the good old top, it just lists the processes by its memory and cpu usage but it can be sorted by processid or name too.

I have the problems with firefox on netbooks too, try out the chromium alpha on launchpad.net if you are ok with bugs ;-)

Answer 5

1- try to switch gnome to gnome/openbox ...

2- try xfce is not fast enough ...

3- try lxde if you want more ...

4- try openbox alone if you wanna make it real fast !!!

5- ditch ubuntu and switch to Arch linux (could be done without the first tips)

IMP: noted in order by ease of use, stability and support ... note that using lightweight alternatives of softwares that you use help also greatly !!!

to replace firefox or chrome there is many others web browsers worth a try like flock a cross-platform social network specialist firefox based browser (I can't ditch firefox customizing ability) or arore (or something like) is a webkit based browser as chrome/chromium ...

IMP: Cruncheee Ubuntu/Openbox based distro for netbook (based on Crunchbang) don't exist for nothing, some peoples have a need for it ...

Answer 6

Dropbox could be taking up some time while syncing. Skype is notoriously difficult to reverse-engineer or troubleshoot.